A thin film transistor-liquid crystal display (TFT-LCD) is composed of a matrix of pixels defined by gate lines and data lines which are in horizontal and vertical directions respectively and intersected to each other. When the TFT-LCD displays, each pixel line is gated (selected) sequentially from top to bottom by gate electrodes (Gate) on the gate lines inputting a square wave with a certain width, and inputted with a desired signal sequentially from top to bottom by source electrodes (Source) of the data lines. When the display has a high resolution, outputs of both the gate electrodes and the source electrodes of the display are of a large number, and the length of the driving circuit will also be increased, which will be adverse to the bonding process for the module driving circuit.
To solve the above problem, in the manufacture of conventional displays, a design of Gate Driver on Array (GOA) circuit is often used. Circuits with thin film transistors (TFTs) as switches are integrated in an array substrate of a display panel to form a display panel scan driver, which can leave out a bonding region and a peripheral wiring space so as to achieve symmetry on both sides of the display panel and an aesthetic design of having a narrow border.
In a conventional GOA circuit design, as shown in FIG. 1 which shows a structure of a shift register unit of a typical GOA circuit, it can be seen that, the shift register unit generally includes a latch 10, an NAND gate 11 and an inverter 12. The latch 10 includes a tri-state gate 101 and a tri-state gate 102 oppositely disposed to each other, and an inverter 103 connected in parallel to the tri-state gate 102. A large number of TFTs will be used in this circuit. When shift register units having the above structure are connected in cascade to form a gate driving circuit, the structure of the gate driving circuit is shown in FIG. 2. Since each of the shift register units have a large number of TFTs, the structure of the GOA circuit becomes complicated and takes up a lot of layout space, which will be adverse to the narrow border design of the display device.